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<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">log</span>(<span class="hljs-params">x, y</span>) </span>{
  y = y || <span class="hljs-string">&apos;World&apos;</span>;
  <span class="hljs-built_in">console</span>.log(x, y);
}
log(<span class="hljs-string">&apos;Hello&apos;</span>) <span class="hljs-comment">// Hello World</span>
log(<span class="hljs-string">&apos;Hello&apos;</span>, <span class="hljs-string">&apos;China&apos;</span>) <span class="hljs-comment">// Hello China</span>
log(<span class="hljs-string">&apos;Hello&apos;</span>, <span class="hljs-string">&apos;&apos;</span>) <span class="hljs-comment">// Hello World</span>
</code></pre>
<p>&#x4E0A;&#x9762;&#x4EE3;&#x7801;&#x68C0;&#x67E5;&#x51FD;&#x6570;<code>log</code>&#x7684;&#x53C2;&#x6570;<code>y</code>&#x6709;&#x6CA1;&#x6709;&#x8D4B;&#x503C;&#xFF0C;&#x5982;&#x679C;&#x6CA1;&#x6709;&#xFF0C;&#x5219;&#x6307;&#x5B9A;&#x9ED8;&#x8BA4;&#x503C;&#x4E3A;<code>World</code>&#x3002;&#x8FD9;&#x79CD;&#x5199;&#x6CD5;&#x7684;&#x7F3A;&#x70B9;&#x5728;&#x4E8E;&#xFF0C;&#x5982;&#x679C;&#x53C2;&#x6570;<code>y</code>&#x8D4B;&#x503C;&#x4E86;&#xFF0C;&#x4F46;&#x662F;&#x5BF9;&#x5E94;&#x7684;&#x5E03;&#x5C14;&#x503C;&#x4E3A;<code>false</code>&#xFF0C;&#x5219;&#x8BE5;&#x8D4B;&#x503C;&#x4E0D;&#x8D77;&#x4F5C;&#x7528;&#x3002;&#x5C31;&#x50CF;&#x4E0A;&#x9762;&#x4EE3;&#x7801;&#x7684;&#x6700;&#x540E;&#x4E00;&#x884C;&#xFF0C;&#x53C2;&#x6570;<code>y</code>&#x7B49;&#x4E8E;&#x7A7A;&#x5B57;&#x7B26;&#xFF0C;&#x7ED3;&#x679C;&#x88AB;&#x6539;&#x4E3A;&#x9ED8;&#x8BA4;&#x503C;&#x3002;</p>
<p>&#x4E3A;&#x4E86;&#x907F;&#x514D;&#x8FD9;&#x4E2A;&#x95EE;&#x9898;&#xFF0C;&#x901A;&#x5E38;&#x9700;&#x8981;&#x5148;&#x5224;&#x65AD;&#x4E00;&#x4E0B;&#x53C2;&#x6570;<code>y</code>&#x662F;&#x5426;&#x88AB;&#x8D4B;&#x503C;&#xFF0C;&#x5982;&#x679C;&#x6CA1;&#x6709;&#xFF0C;&#x518D;&#x7B49;&#x4E8E;&#x9ED8;&#x8BA4;&#x503C;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">if</span> (<span class="hljs-keyword">typeof</span> y === <span class="hljs-string">&apos;undefined&apos;</span>) {
  y = <span class="hljs-string">&apos;World&apos;</span>;
}
</code></pre>
<p>ES6 &#x5141;&#x8BB8;&#x4E3A;&#x51FD;&#x6570;&#x7684;&#x53C2;&#x6570;&#x8BBE;&#x7F6E;&#x9ED8;&#x8BA4;&#x503C;&#xFF0C;&#x5373;&#x76F4;&#x63A5;&#x5199;&#x5728;&#x53C2;&#x6570;&#x5B9A;&#x4E49;&#x7684;&#x540E;&#x9762;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">log</span>(<span class="hljs-params">x, y = &apos;World&apos;</span>) </span>{
  <span class="hljs-built_in">console</span>.log(x, y);
}

log(<span class="hljs-string">&apos;Hello&apos;</span>) <span class="hljs-comment">// Hello World</span>
log(<span class="hljs-string">&apos;Hello&apos;</span>, <span class="hljs-string">&apos;China&apos;</span>) <span class="hljs-comment">// Hello China</span>
log(<span class="hljs-string">&apos;Hello&apos;</span>, <span class="hljs-string">&apos;&apos;</span>) <span class="hljs-comment">// Hello</span>
</code></pre>
<p>&#x53E6;&#x5916;&#xFF0C;&#x4E00;&#x4E2A;&#x5BB9;&#x6613;&#x5FFD;&#x7565;&#x7684;&#x5730;&#x65B9;&#x662F;&#xFF0C;&#x53C2;&#x6570;&#x9ED8;&#x8BA4;&#x503C;&#x4E0D;&#x662F;&#x4F20;&#x503C;&#x7684;&#xFF0C;&#x800C;&#x662F;&#x6BCF;&#x6B21;&#x90FD;&#x91CD;&#x65B0;&#x8BA1;&#x7B97;&#x9ED8;&#x8BA4;&#x503C;&#x8868;&#x8FBE;&#x5F0F;&#x7684;&#x503C;&#x3002;&#x4E5F;&#x5C31;&#x662F;&#x8BF4;&#xFF0C;&#x53C2;&#x6570;&#x9ED8;&#x8BA4;&#x503C;&#x662F;&#x60F0;&#x6027;&#x6C42;&#x503C;&#x7684;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">let</span> x = <span class="hljs-number">99</span>;
<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">foo</span>(<span class="hljs-params">p = x + 1</span>) </span>{
  <span class="hljs-built_in">console</span>.log(p);
}

foo() <span class="hljs-comment">// 100</span>

x = <span class="hljs-number">100</span>;
foo() <span class="hljs-comment">// 101</span>
</code></pre>
<p>&#x4E0A;&#x9762;&#x4EE3;&#x7801;&#x4E2D;&#xFF0C;&#x53C2;&#x6570;<code>p</code>&#x7684;&#x9ED8;&#x8BA4;&#x503C;&#x662F;<code>x + 1</code>&#x3002;&#x8FD9;&#x65F6;&#xFF0C;&#x6BCF;&#x6B21;&#x8C03;&#x7528;&#x51FD;&#x6570;<code>foo</code>&#xFF0C;&#x90FD;&#x4F1A;&#x91CD;&#x65B0;&#x8BA1;&#x7B97;<code>x + 1</code>&#xFF0C;&#x800C;&#x4E0D;&#x662F;&#x9ED8;&#x8BA4;<code>p</code>&#x7B49;&#x4E8E; 100&#x3002;</p>
<h3 id="&#x51FD;&#x6570;&#x7684;-length-&#x5C5E;&#x6027;">&#x51FD;&#x6570;&#x7684; length &#x5C5E;&#x6027;</h3>
<p>&#x6307;&#x5B9A;&#x4E86;&#x9ED8;&#x8BA4;&#x503C;&#x4EE5;&#x540E;&#xFF0C;&#x51FD;&#x6570;&#x7684;<code>length</code>&#x5C5E;&#x6027;&#xFF0C;&#x5C06;&#x8FD4;&#x56DE;&#x6CA1;&#x6709;&#x6307;&#x5B9A;&#x9ED8;&#x8BA4;&#x503C;&#x7684;&#x53C2;&#x6570;&#x4E2A;&#x6570;&#x3002;&#x4E5F;&#x5C31;&#x662F;&#x8BF4;&#xFF0C;&#x6307;&#x5B9A;&#x4E86;&#x9ED8;&#x8BA4;&#x503C;&#x540E;&#xFF0C;<code>length</code>&#x5C5E;&#x6027;&#x5C06;&#x5931;&#x771F;&#x3002;</p>
<pre><code class="lang-javascript">(<span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">a</span>) </span>{}).length <span class="hljs-comment">// 1</span>
(<span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">a = 5</span>) </span>{}).length <span class="hljs-comment">// 0</span>
(<span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">a, b, c = 5</span>) </span>{}).length <span class="hljs-comment">// 2</span>
</code></pre>
<p>&#x5982;&#x679C;&#x8BBE;&#x7F6E;&#x4E86;&#x9ED8;&#x8BA4;&#x503C;&#x7684;&#x53C2;&#x6570;&#x4E0D;&#x662F;&#x5C3E;&#x53C2;&#x6570;&#xFF0C;&#x90A3;&#x4E48;<code>length</code>&#x5C5E;&#x6027;&#x4E5F;&#x4E0D;&#x518D;&#x8BA1;&#x5165;&#x540E;&#x9762;&#x7684;&#x53C2;&#x6570;&#x4E86;&#x3002;</p>
<pre><code class="lang-javascript">(<span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">a = 0, b, c</span>) </span>{}).length <span class="hljs-comment">// 0</span>
(<span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">a, b = 1, c</span>) </span>{}).length <span class="hljs-comment">// 1</span>
</code></pre>
<h3 id="&#x4F5C;&#x7528;&#x57DF;">&#x4F5C;&#x7528;&#x57DF;</h3>
<p>&#x4E00;&#x65E6;&#x8BBE;&#x7F6E;&#x4E86;&#x53C2;&#x6570;&#x7684;&#x9ED8;&#x8BA4;&#x503C;&#xFF0C;&#x51FD;&#x6570;&#x8FDB;&#x884C;&#x58F0;&#x660E;&#x521D;&#x59CB;&#x5316;&#x65F6;&#xFF0C;&#x53C2;&#x6570;&#x4F1A;&#x5F62;&#x6210;&#x4E00;&#x4E2A;&#x5355;&#x72EC;&#x7684;&#x4F5C;&#x7528;&#x57DF;&#xFF08;context&#xFF09;&#x3002;&#x7B49;&#x5230;&#x521D;&#x59CB;&#x5316;&#x7ED3;&#x675F;&#xFF0C;&#x8FD9;&#x4E2A;&#x4F5C;&#x7528;&#x57DF;&#x5C31;&#x4F1A;&#x6D88;&#x5931;&#x3002;&#x8FD9;&#x79CD;&#x8BED;&#x6CD5;&#x884C;&#x4E3A;&#xFF0C;&#x5728;&#x4E0D;&#x8BBE;&#x7F6E;&#x53C2;&#x6570;&#x9ED8;&#x8BA4;&#x503C;&#x65F6;&#xFF0C;&#x662F;&#x4E0D;&#x4F1A;&#x51FA;&#x73B0;&#x7684;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> x = <span class="hljs-number">1</span>;

<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">f</span>(<span class="hljs-params">x, y = x</span>) </span>{
  <span class="hljs-built_in">console</span>.log(y);
}

f(<span class="hljs-number">2</span>) <span class="hljs-comment">// 2</span>
</code></pre>
<p>&#x4E0A;&#x9762;&#x4EE3;&#x7801;&#x4E2D;&#xFF0C;&#x53C2;&#x6570;<code>y</code>&#x7684;&#x9ED8;&#x8BA4;&#x503C;&#x7B49;&#x4E8E;&#x53D8;&#x91CF;<code>x</code>&#x3002;&#x8C03;&#x7528;&#x51FD;&#x6570;<code>f</code>&#x65F6;&#xFF0C;&#x53C2;&#x6570;&#x5F62;&#x6210;&#x4E00;&#x4E2A;&#x5355;&#x72EC;&#x7684;&#x4F5C;&#x7528;&#x57DF;&#x3002;&#x5728;&#x8FD9;&#x4E2A;&#x4F5C;&#x7528;&#x57DF;&#x91CC;&#x9762;&#xFF0C;&#x9ED8;&#x8BA4;&#x503C;&#x53D8;&#x91CF;<code>x</code>&#x6307;&#x5411;&#x7B2C;&#x4E00;&#x4E2A;&#x53C2;&#x6570;<code>x</code>&#xFF0C;&#x800C;&#x4E0D;&#x662F;&#x5168;&#x5C40;&#x53D8;&#x91CF;<code>x</code>&#xFF0C;&#x6240;&#x4EE5;&#x8F93;&#x51FA;&#x662F;<code>2</code>&#x3002;</p>
<p>&#x518D;&#x770B;&#x4E0B;&#x9762;&#x7684;&#x4F8B;&#x5B50;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">let</span> x = <span class="hljs-number">1</span>;

<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">f</span>(<span class="hljs-params">y = x</span>) </span>{
  <span class="hljs-keyword">let</span> x = <span class="hljs-number">2</span>;
  <span class="hljs-built_in">console</span>.log(y);
}

f() <span class="hljs-comment">// 1</span>
</code></pre>
<p>&#x4E0A;&#x9762;&#x4EE3;&#x7801;&#x4E2D;&#xFF0C;&#x51FD;&#x6570;<code>f</code>&#x8C03;&#x7528;&#x65F6;&#xFF0C;&#x53C2;&#x6570;<code>y = x</code>&#x5F62;&#x6210;&#x4E00;&#x4E2A;&#x5355;&#x72EC;&#x7684;&#x4F5C;&#x7528;&#x57DF;&#x3002;&#x8FD9;&#x4E2A;&#x4F5C;&#x7528;&#x57DF;&#x91CC;&#x9762;&#xFF0C;&#x53D8;&#x91CF;<code>x</code>&#x672C;&#x8EAB;&#x6CA1;&#x6709;&#x5B9A;&#x4E49;&#xFF0C;&#x6240;&#x4EE5;&#x6307;&#x5411;&#x5916;&#x5C42;&#x7684;&#x5168;&#x5C40;&#x53D8;&#x91CF;<code>x</code>&#x3002;&#x51FD;&#x6570;&#x8C03;&#x7528;&#x65F6;&#xFF0C;&#x51FD;&#x6570;&#x4F53;&#x5185;&#x90E8;&#x7684;&#x5C40;&#x90E8;&#x53D8;&#x91CF;<code>x</code>&#x5F71;&#x54CD;&#x4E0D;&#x5230;&#x9ED8;&#x8BA4;&#x503C;&#x53D8;&#x91CF;<code>x</code>&#x3002;</p>
<h2 id="name-&#x5C5E;&#x6027;">name &#x5C5E;&#x6027;</h2>
<p>&#x51FD;&#x6570;&#x7684;<code>name</code>&#x5C5E;&#x6027;&#xFF0C;&#x8FD4;&#x56DE;&#x8BE5;&#x51FD;&#x6570;&#x7684;&#x51FD;&#x6570;&#x540D;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">foo</span>(<span class="hljs-params"></span>) </span>{}
foo.name <span class="hljs-comment">// &quot;foo&quot;</span>
</code></pre>
<p>&#x8FD9;&#x4E2A;&#x5C5E;&#x6027;&#x65E9;&#x5C31;&#x88AB;&#x6D4F;&#x89C8;&#x5668;&#x5E7F;&#x6CDB;&#x652F;&#x6301;&#xFF0C;&#x4F46;&#x662F;&#x76F4;&#x5230; ES6&#xFF0C;&#x624D;&#x5C06;&#x5176;&#x5199;&#x5165;&#x4E86;&#x6807;&#x51C6;&#x3002;</p>
<p>&#x9700;&#x8981;&#x6CE8;&#x610F;&#x7684;&#x662F;&#xFF0C;ES6 &#x5BF9;&#x8FD9;&#x4E2A;&#x5C5E;&#x6027;&#x7684;&#x884C;&#x4E3A;&#x505A;&#x51FA;&#x4E86;&#x4E00;&#x4E9B;&#x4FEE;&#x6539;&#x3002;&#x5982;&#x679C;&#x5C06;&#x4E00;&#x4E2A;&#x533F;&#x540D;&#x51FD;&#x6570;&#x8D4B;&#x503C;&#x7ED9;&#x4E00;&#x4E2A;&#x53D8;&#x91CF;&#xFF0C;ES5 &#x7684;<code>name</code>&#x5C5E;&#x6027;&#xFF0C;&#x4F1A;&#x8FD4;&#x56DE;&#x7A7A;&#x5B57;&#x7B26;&#x4E32;&#xFF0C;&#x800C; ES6 &#x7684;<code>name</code>&#x5C5E;&#x6027;&#x4F1A;&#x8FD4;&#x56DE;&#x5B9E;&#x9645;&#x7684;&#x51FD;&#x6570;&#x540D;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> f = <span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params"></span>) </span>{};

<span class="hljs-comment">// ES5</span>
f.name <span class="hljs-comment">// &quot;&quot;</span>

<span class="hljs-comment">// ES6</span>
f.name <span class="hljs-comment">// &quot;f&quot;</span>
</code></pre>
<h3 id="&#x5C3E;&#x9012;&#x5F52;">&#x5C3E;&#x9012;&#x5F52;</h3>
<p>&#x51FD;&#x6570;&#x8C03;&#x7528;&#x81EA;&#x8EAB;&#xFF0C;&#x79F0;&#x4E3A;&#x9012;&#x5F52;&#x3002;&#x5982;&#x679C;&#x5C3E;&#x8C03;&#x7528;&#x81EA;&#x8EAB;&#xFF0C;&#x5C31;&#x79F0;&#x4E3A;&#x5C3E;&#x9012;&#x5F52;&#x3002;</p>
<p>&#x9012;&#x5F52;&#x975E;&#x5E38;&#x8017;&#x8D39;&#x5185;&#x5B58;&#xFF0C;&#x56E0;&#x4E3A;&#x9700;&#x8981;&#x540C;&#x65F6;&#x4FDD;&#x5B58;&#x6210;&#x5343;&#x4E0A;&#x767E;&#x4E2A;&#x8C03;&#x7528;&#x5E27;&#xFF0C;&#x5F88;&#x5BB9;&#x6613;&#x53D1;&#x751F;&#x201C;&#x6808;&#x6EA2;&#x51FA;&#x201D;&#x9519;&#x8BEF;&#xFF08;stack overflow&#xFF09;&#x3002;&#x4F46;&#x5BF9;&#x4E8E;&#x5C3E;&#x9012;&#x5F52;&#x6765;&#x8BF4;&#xFF0C;&#x7531;&#x4E8E;&#x53EA;&#x5B58;&#x5728;&#x4E00;&#x4E2A;&#x8C03;&#x7528;&#x5E27;&#xFF0C;&#x6240;&#x4EE5;&#x6C38;&#x8FDC;&#x4E0D;&#x4F1A;&#x53D1;&#x751F;&#x201C;&#x6808;&#x6EA2;&#x51FA;&#x201D;&#x9519;&#x8BEF;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">factorial</span>(<span class="hljs-params">n</span>) </span>{
  <span class="hljs-keyword">if</span> (n === <span class="hljs-number">1</span>) <span class="hljs-keyword">return</span> <span class="hljs-number">1</span>;
  <span class="hljs-keyword">return</span> n * factorial(n - <span class="hljs-number">1</span>);
}

factorial(<span class="hljs-number">5</span>) <span class="hljs-comment">// 120</span>
</code></pre>
<p>&#x4E0A;&#x9762;&#x4EE3;&#x7801;&#x662F;&#x4E00;&#x4E2A;&#x9636;&#x4E58;&#x51FD;&#x6570;&#xFF0C;&#x8BA1;&#x7B97;<code>n</code>&#x7684;&#x9636;&#x4E58;&#xFF0C;&#x6700;&#x591A;&#x9700;&#x8981;&#x4FDD;&#x5B58;<code>n</code>&#x4E2A;&#x8C03;&#x7528;&#x8BB0;&#x5F55;&#xFF0C;&#x590D;&#x6742;&#x5EA6; O(n) &#x3002;</p>
<p>&#x5982;&#x679C;&#x6539;&#x5199;&#x6210;&#x5C3E;&#x9012;&#x5F52;&#xFF0C;&#x53EA;&#x4FDD;&#x7559;&#x4E00;&#x4E2A;&#x8C03;&#x7528;&#x8BB0;&#x5F55;&#xFF0C;&#x590D;&#x6742;&#x5EA6; O(1) &#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">factorial</span>(<span class="hljs-params">n, total</span>) </span>{
  <span class="hljs-keyword">if</span> (n === <span class="hljs-number">1</span>) <span class="hljs-keyword">return</span> total;
  <span class="hljs-keyword">return</span> factorial(n - <span class="hljs-number">1</span>, n * total);
}

factorial(<span class="hljs-number">5</span>, <span class="hljs-number">1</span>) <span class="hljs-comment">// 120</span>
</code></pre>
<p>&#x8FD8;&#x6709;&#x4E00;&#x4E2A;&#x6BD4;&#x8F83;&#x8457;&#x540D;&#x7684;&#x4F8B;&#x5B50;&#xFF0C;&#x5C31;&#x662F;&#x8BA1;&#x7B97; Fibonacci &#x6570;&#x5217;&#xFF0C;&#x4E5F;&#x80FD;&#x5145;&#x5206;&#x8BF4;&#x660E;&#x5C3E;&#x9012;&#x5F52;&#x4F18;&#x5316;&#x7684;&#x91CD;&#x8981;&#x6027;&#x3002;</p>
<p>&#x975E;&#x5C3E;&#x9012;&#x5F52;&#x7684; Fibonacci &#x6570;&#x5217;&#x5B9E;&#x73B0;&#x5982;&#x4E0B;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">Fibonacci</span> (<span class="hljs-params">n</span>) </span>{
  <span class="hljs-keyword">if</span> ( n &lt;= <span class="hljs-number">1</span> ) {<span class="hljs-keyword">return</span> <span class="hljs-number">1</span>};

  <span class="hljs-keyword">return</span> Fibonacci(n - <span class="hljs-number">1</span>) + Fibonacci(n - <span class="hljs-number">2</span>);
}

Fibonacci(<span class="hljs-number">10</span>) <span class="hljs-comment">// 89</span>
Fibonacci(<span class="hljs-number">100</span>) <span class="hljs-comment">// &#x8D85;&#x65F6;</span>
Fibonacci(<span class="hljs-number">500</span>) <span class="hljs-comment">// &#x8D85;&#x65F6;</span>
</code></pre>
<p>&#x5C3E;&#x9012;&#x5F52;&#x4F18;&#x5316;&#x8FC7;&#x7684; Fibonacci &#x6570;&#x5217;&#x5B9E;&#x73B0;&#x5982;&#x4E0B;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">Fibonacci2</span> (<span class="hljs-params">n , ac1 = 1 , ac2 = 1</span>) </span>{
  <span class="hljs-keyword">if</span>( n &lt;= <span class="hljs-number">1</span> ) {<span class="hljs-keyword">return</span> ac2};

  <span class="hljs-keyword">return</span> Fibonacci2 (n - <span class="hljs-number">1</span>, ac2, ac1 + ac2);
}

Fibonacci2(<span class="hljs-number">100</span>) <span class="hljs-comment">// 573147844013817200000</span>
Fibonacci2(<span class="hljs-number">1000</span>) <span class="hljs-comment">// 7.0330367711422765e+208</span>
Fibonacci2(<span class="hljs-number">10000</span>) <span class="hljs-comment">// Infinity</span>
</code></pre>
<p>&#x7531;&#x6B64;&#x53EF;&#x89C1;&#xFF0C;&#x201C;&#x5C3E;&#x8C03;&#x7528;&#x4F18;&#x5316;&#x201D;&#x5BF9;&#x9012;&#x5F52;&#x64CD;&#x4F5C;&#x610F;&#x4E49;&#x91CD;&#x5927;&#xFF0C;&#x6240;&#x4EE5;&#x4E00;&#x4E9B;&#x51FD;&#x6570;&#x5F0F;&#x7F16;&#x7A0B;&#x8BED;&#x8A00;&#x5C06;&#x5176;&#x5199;&#x5165;&#x4E86;&#x8BED;&#x8A00;&#x89C4;&#x683C;&#x3002;ES6 &#x4EA6;&#x662F;&#x5982;&#x6B64;&#xFF0C;&#x7B2C;&#x4E00;&#x6B21;&#x660E;&#x786E;&#x89C4;&#x5B9A;&#xFF0C;&#x6240;&#x6709; ECMAScript &#x7684;&#x5B9E;&#x73B0;&#xFF0C;&#x90FD;&#x5FC5;&#x987B;&#x90E8;&#x7F72;&#x201C;&#x5C3E;&#x8C03;&#x7528;&#x4F18;&#x5316;&#x201D;&#x3002;&#x8FD9;&#x5C31;&#x662F;&#x8BF4;&#xFF0C;ES6 &#x4E2D;&#x53EA;&#x8981;&#x4F7F;&#x7528;&#x5C3E;&#x9012;&#x5F52;&#xFF0C;&#x5C31;&#x4E0D;&#x4F1A;&#x53D1;&#x751F;&#x6808;&#x6EA2;&#x51FA;&#xFF08;&#x6216;&#x8005;&#x5C42;&#x5C42;&#x9012;&#x5F52;&#x9020;&#x6210;&#x7684;&#x8D85;&#x65F6;&#xFF09;&#xFF0C;&#x76F8;&#x5BF9;&#x8282;&#x7701;&#x5185;&#x5B58;&#x3002;</p>
<h2 id="&#x51FD;&#x6570;&#x53C2;&#x6570;&#x7684;&#x5C3E;&#x9017;&#x53F7;">&#x51FD;&#x6570;&#x53C2;&#x6570;&#x7684;&#x5C3E;&#x9017;&#x53F7;</h2>
<p>ES2017 <a href="https://github.com/jeffmo/es-trailing-function-commas" target="_blank">&#x5141;&#x8BB8;</a>&#x51FD;&#x6570;&#x7684;&#x6700;&#x540E;&#x4E00;&#x4E2A;&#x53C2;&#x6570;&#x6709;&#x5C3E;&#x9017;&#x53F7;&#xFF08;trailing comma&#xFF09;&#x3002;</p>
<p>&#x6B64;&#x524D;&#xFF0C;&#x51FD;&#x6570;&#x5B9A;&#x4E49;&#x548C;&#x8C03;&#x7528;&#x65F6;&#xFF0C;&#x90FD;&#x4E0D;&#x5141;&#x8BB8;&#x6700;&#x540E;&#x4E00;&#x4E2A;&#x53C2;&#x6570;&#x540E;&#x9762;&#x51FA;&#x73B0;&#x9017;&#x53F7;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">clownsEverywhere</span>(<span class="hljs-params">
  param1,
  param2
</span>) </span>{ <span class="hljs-comment">/* ... */</span> }

clownsEverywhere(
  <span class="hljs-string">&apos;foo&apos;</span>,
  <span class="hljs-string">&apos;bar&apos;</span>
);
</code></pre>
<p>&#x4E0A;&#x9762;&#x4EE3;&#x7801;&#x4E2D;&#xFF0C;&#x5982;&#x679C;&#x5728;<code>param2</code>&#x6216;<code>bar</code>&#x540E;&#x9762;&#x52A0;&#x4E00;&#x4E2A;&#x9017;&#x53F7;&#xFF0C;&#x5C31;&#x4F1A;&#x62A5;&#x9519;&#x3002;</p>
<p>&#x5982;&#x679C;&#x50CF;&#x4E0A;&#x9762;&#x8FD9;&#x6837;&#xFF0C;&#x5C06;&#x53C2;&#x6570;&#x5199;&#x6210;&#x591A;&#x884C;&#xFF08;&#x5373;&#x6BCF;&#x4E2A;&#x53C2;&#x6570;&#x5360;&#x636E;&#x4E00;&#x884C;&#xFF09;&#xFF0C;&#x4EE5;&#x540E;&#x4FEE;&#x6539;&#x4EE3;&#x7801;&#x7684;&#x65F6;&#x5019;&#xFF0C;&#x60F3;&#x4E3A;&#x51FD;&#x6570;<code>clownsEverywhere</code>&#x6DFB;&#x52A0;&#x7B2C;&#x4E09;&#x4E2A;&#x53C2;&#x6570;&#xFF0C;&#x6216;&#x8005;&#x8C03;&#x6574;&#x53C2;&#x6570;&#x7684;&#x6B21;&#x5E8F;&#xFF0C;&#x5C31;&#x52BF;&#x5FC5;&#x8981;&#x5728;&#x539F;&#x6765;&#x6700;&#x540E;&#x4E00;&#x4E2A;&#x53C2;&#x6570;&#x540E;&#x9762;&#x6DFB;&#x52A0;&#x4E00;&#x4E2A;&#x9017;&#x53F7;&#x3002;&#x8FD9;&#x5BF9;&#x4E8E;&#x7248;&#x672C;&#x7BA1;&#x7406;&#x7CFB;&#x7EDF;&#x6765;&#x8BF4;&#xFF0C;&#x5C31;&#x4F1A;&#x663E;&#x793A;&#x6DFB;&#x52A0;&#x9017;&#x53F7;&#x7684;&#x90A3;&#x4E00;&#x884C;&#x4E5F;&#x53D1;&#x751F;&#x4E86;&#x53D8;&#x52A8;&#x3002;&#x8FD9;&#x770B;&#x4E0A;&#x53BB;&#x6709;&#x70B9;&#x5197;&#x4F59;&#xFF0C;&#x56E0;&#x6B64;&#x65B0;&#x7684;&#x8BED;&#x6CD5;&#x5141;&#x8BB8;&#x5B9A;&#x4E49;&#x548C;&#x8C03;&#x7528;&#x65F6;&#xFF0C;&#x5C3E;&#x90E8;&#x76F4;&#x63A5;&#x6709;&#x4E00;&#x4E2A;&#x9017;&#x53F7;&#x3002;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">clownsEverywhere</span>(<span class="hljs-params">
  param1,
  param2,
</span>) </span>{ <span class="hljs-comment">/* ... */</span> }

clownsEverywhere(
  <span class="hljs-string">&apos;foo&apos;</span>,
  <span class="hljs-string">&apos;bar&apos;</span>,
);
</code></pre>
<p>&#x8FD9;&#x6837;&#x7684;&#x89C4;&#x5B9A;&#x4E5F;&#x4F7F;&#x5F97;&#xFF0C;&#x51FD;&#x6570;&#x53C2;&#x6570;&#x4E0E;&#x6570;&#x7EC4;&#x548C;&#x5BF9;&#x8C61;&#x7684;&#x5C3E;&#x9017;&#x53F7;&#x89C4;&#x5219;&#xFF0C;&#x4FDD;&#x6301;&#x4E00;&#x81F4;&#x4E86;&#x3002;</p>

                                
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